Thursday, April 24, 2014

A Demonstration by Stephen Hatcher

I took a few moments a week or so ago to sit in on a demonstration in Inlay for Woodturning & Flatwork with Stephen Hatcher. I was sure I would see something interesting (...always do), but I was completely unprepared for the visual impact that an inlay of crushed minerals could give a piece; especially when it's set into a delicate groove around the rim of a bowl or platter. All the information I had going in was Mark Hedin saying, "Hatcher's about to do a cool demo!" and that's all I needed to hear. What did I learn? It's really easy to do, once you understand the process!

I joined the class as Stephen began demonstrating how he inlays the rims of his turned bowls and platters with crushed minerals set into a colored background. All he uses was a very thin CA glue, black pigment, crushed calcite (a light green mineral), a modified thin kerf parting tool and a one tenth of a pound (that's right, 1/10th ) cut of wax-free shellac in an industrial spray bottle. That (and 20-30 minutes) are all that you need, once you know how it's done.

The first step in the process is to cut a 1/8" to 1/4" groove (or grooves) into the rim of the bowl (in this case, maple). Stephen used a modified, thin kerf parting tool which has been reshaped to provide extra clearance. By removing most of the height of the tool, along with a tapered grind (widest at the top of the cutting edge) he creates a tool that can cut hard maple without any tear-out (or burning) of the wood.

After cutting the groove (or grooves) to receive the crushed minerals, he thoroughly sprays the bowl with his 1/10 lb cut of dewaxedshellac. And by thorough, I mean it's dripping wet. This is how he seals the wood to prevent the colored pigment and the CA glue from staining the wood.

Once the shellac dries, he generously applies his colored powder, in this case, black cement dye, into the recess he just created. By creating this colored background, he increases the contrast between the wood and the mineral crystals so that the different colors really "pop".

Next he crushed some calcite (it's light green and semi-translucent) in an old teapot with the blunt end of of a cement chisel and sorted it into 3 different sizes - course, medium and fine. He used old cast off food strainers with different size meshes to quickly separate the different sizes of crystal. Stephen claims everything you need to incorporate crushed minerals in your projects can likely be found at your local Goodwill store! Anyway, when he was done, he had 3 different sizes of crushed calcite.

Now he loaded the recess with the different size crystals, beginning with the largest that will just fit within the groove. After adding the largest, proceed to fill in the gaps left with the medium and fine crystals until you have filled just proud of the top of the groove. Finish up by covering the minerals with more of the colored powder. You can touch a running Dremel's tool housing to the side of the bowl to help vibrate the crystals & powder into place. Sweep any residue from around the groove with a acid brush. At this point, things aren't looking too spectacular...yet.

Now it's time to apply the thin CA glue - and by thin, I mean very, very thin. Stephen uses Starbond EM-02 with good results. Go around the groove applying CA glue as you go. You will need to make several trips around the rim to build up enough of the CA glue to fill the groove. Stephen recommends continuing until you see the top of the groove become shiny. You will use a LOT of the glue to achieve this. Remember I said above that things didn't look too spectacular. Now it looks like a real mess. But not to worry - beneath the surface, things are great. All that's left now is to remove that surface to reveal the inner beauty.

So out comes the power drill and an automotive detailing pad adapted to the chuck on drill. With P60 hook & loop sandpaper attached, Stephen mounted the bowl on the lathe and began sanding off the excess colored CA glue / mineral composite. He did this first with the lathe switched off, and then with the lathe on once the majority of the material was ground away. He then proceeded through the P80 and P100 grits. Next he reapplied the dilute shellac.

All that was left to do is fill in any voids with more black powder and CA glue and re-sand, repeating until the process until all the voids are filled and the surface of inlay is ready for final sanding. While there's still plenty of cleanup left to do at this point, you can see we are well on the way to an outstanding embellishment!

And here are some more examples from the students in the class.

If you'd like to learn even more about inlaying minerals in your projects, check out the Techniques section on Stephen Hatcher's website. He has some great articles with lots more information. Here are links to two with more information presented in Stephen's demonstration....